#include <stdio.h>

int main() {
    int n = 0;
    int s = 0;
    scanf_s("%d", &n);
    if (n < 12) 
    {
        printf("2");
    }
    else
    {
        s = n / 12  * 4 ;
        printf("%d", s+2);
    }
    return 0;
}